The present invention relates to the field of air conditioning systems, and, more particularly, to a system and method for removing salt, dirt, etc., from air conditioning components.
Air conditioners have long been used to provide comfortable air temperatures inside buildings. One type of air conditioning system which enjoys widespread use is the central heating and air conditioning system. Such systems typically include an indoor unit inside a building including a heat exchanger which transfers heat from air in the building to a refrigerant inside the heat exchanger. The refrigerant is then pumped outside the building by a compressor to an outdoor heat exchanger located in an outdoor unit where the heat is then transferred to the outside air.
Central heating/air conditioning systems can also be operated in a reverse manner (i.e., as heat pumps) during colder months to bring heat from the outside air into the building. While heat pumps generally cannot provide large amounts of heat as efficiently as a furnace, for example, they typically are able to provide adequate heat in regions that have fairly mild winters.
As such, central heating/air conditioning systems are particularly well suited for warmer climates, including coastal environments. In such environments the high quantity of corrosive salts in the air often causes various components of air conditioning systems to corrode, particularly the outdoor unit components which are continuously exposed to salt air. For example, the copper tubing used to make heat exchanger assemblies is particularly susceptible to corrosion from salts, as may also be certain parts of the fan used to blow outside air through the outdoor heat exchanger. Moreover, in other environments where coils, fans, etc. tend to have a large amount of dirt or other debris accumulate thereon, this may also tend to decrease component lifespan in addition to reducing system performance.
Some prior art systems have attempted to address the effects of corrosive particles on certain air conditioning system components. By way of example, U.S. Pat. No. 6,182,741 to Yoshii et al. is directed to an air conditioner for preventing corrosion of an evaporator heat exchanger. The air conditioner includes a case and an evaporator therein having a core portion and a lower tank at a bottom of the core portion. The case has a recess portion at an upstream air side of the evaporator, and a covering wall extends upwardly from the bottom of the recess portion to cover only the lower tank at an immediately upstream air side. When air passes through the evaporator, corrosive substances in the air collide with the evaporator and fall in the recess portion. As such, the corrosive substances do not directly adhere to the lower tank of the evaporator, which reduces evaporator corrosion.
A somewhat similar air conditioner is described in Japanese Patent No. 63-150540 to Yasuhiro. This air conditioner includes a condensation chamber which is filled with humidified air to remove salt particles from air being taken into the system. This is done to reduce the accumulation of such particles on a filter, and thus premature pressure loss. Moreover, the reduction in salt particles in the air also helps to prevent corrosion of a blower downstream from the condensation chamber.
While the above systems may be helpful in reducing corrosion of central air conditioning system components inside a building (i.e., the evaporator and blower), they provide no such protection for outdoor components. As such, apart from persistent manual cleanings, there has heretofore been no convenient way to reduce the accumulation of corrosive or other particles on outdoor air conditioning system components. Thus, such components require replacement on a more frequent basis, and system performance may suffer, when used in corrosive or dirty environments.
In view of the foregoing background, it is therefore an object of the present invention to provide an air conditioning system and associated methods which reduce the accumulation of salts, dirt and other contaminants on outdoor system components which may lead to system performance degradation and/or premature component failure.
This and other objects, features, and advantages in accordance with the present invention are provided by an air conditioning system including an indoor heat exchanger to be positioned within a building and including a refrigerant for exchanging heat with air inside the building, and an outdoor unit to be positioned outside of the building. The outdoor unit may include a housing and an outdoor heat exchanger carried by the housing. Further, the outdoor heat exchanger may be connected in fluid communication with the indoor heat exchanger for exchanging heat between the refrigerant and air outside the building. The air conditioning system may also include a compressor for circulating the refrigerant between the indoor heat exchanger and the outdoor heat exchanger.
Additionally, the system may further include a liquid washdown dispenser carried by the housing adjacent the outdoor heat exchanger. In particular, the liquid washdown dispenser may be connected to a liquid dispensing source for dispensing liquid (e.g., fresh water) to wash down the outdoor heat exchanger. Further, a controller may also be included for controlling liquid flow to the liquid washdown dispenser. Accordingly, the controller and liquid washdown dispenser advantageously cooperate to remove potentially corrosive or harmful particles from the outdoor heat exchanger before significant component or system performance degradation results.
More particularly, the outdoor unit may also include a fan carried by the housing for circulating outside air through the outdoor heat exchanger, and the liquid washdown dispenser may also dispense liquid to wash down the fan. The outdoor unit may also be switchable between on and off states, and the controller may prohibit liquid flow to the liquid washdown dispenser when the outdoor unit is in the on state. As such, the liquid will not be sprayed outside of the outdoor unit by the fan, for example.
Furthermore, the controller may also include a timer for periodically causing the liquid flow to be turned on and off. Thus, the timer may be set to provide liquid dispensing at desired intervals and for a predetermined duration so that wash downs are performed frequently enough to adequately reduce corrosion, yet while not wasting liquid/fresh water. In particular, the controller may further include a valve connecting the liquid washdown dispenser to the liquid dispensing source, and a solenoid connected between the timer and the valve.
The liquid washdown dispenser may include a plurality of nozzles adjacent the outdoor heat exchanger and tubing connecting the nozzles to the liquid dispensing source. In addition, the housing may have openings therein to permit air flow, and the outdoor heat exchanger may be positioned adjacent the at least one side.
A method aspect of the invention is for retrofitting an outdoor unit of an air conditioning system to be positioned outside of a building, such as the one described briefly above. The method may include mounting a liquid washdown dispenser in the housing adjacent the outdoor heat exchanger, and connecting the liquid washdown dispenser to a liquid dispensing source for dispensing liquid to wash down the outdoor heat exchanger. In addition, the method may also include connecting a controller to the liquid dispensing source for controlling liquid flow to the liquid washdown dispenser.